Last Updated on 2020-11-08 by aeno
When you’re running Magento 2 inside a Docker container (for example for local development) and you’re using a non-standard TLS port (or SSL port) like 44333, then your back-end adminhtml route will trigger a 404 error.
The Solution: Even if it seems to be redundant, set a custom admin URL.
Set admin/url/use_custom to 1 and admin/url/custom to your back-end’s full URL including non-standard port: https://my.site:44333/admin.